THE CLOACA AND SPERMATHECA OF HEMIDACTY- 



LIUM SCUTATUM. 



JOHANNA M. DIECKMANN, 

 DEPARTMENT OF ANATOMY, SCHOOL OF MEDICINE, UNIVERSITY OF BUFFALO. 



Two specimens of adult female H emidactylium scutatum were 

 examined, one measuring 7.1 and the other 7.7 cm., both captured 

 in August. 1 After fixation in Bouin's fluid, the cloacae were sec- 

 tioned, one transversely and one sagittally, at 12^ and 10^1 re- 

 spectively. The ova of both animals were less than i.o mm. in 

 diameter, since ovulation in this species occurs during May 

 (Bishop, '18). 



The cloaca of H emidactylium, when empty, is slit-like, with its 

 lateral walls thrown into quite regular folds. Two such folds, 

 located in the dorsal wall of the cloaca, and first discernible at the 

 level of the cephalic end of the vent, become fairly tall as one 

 passes cephalad. These two together constitute the dorsal ele- 

 vation, which though varying in form, appears in the cloaca of 

 the female in several urodeles (Kingsbury, '95). The slit between 

 the two folds or limbs of the dorsal elevation is continuous caudally 

 with the roof of the cloaca over the region of the vent, and cepha- 

 lad, with a dorsal expansion of the cloaca, into which, as in other 

 forms, the ureters and oviducts open. In other words, the two 

 limbs of the elevation are not fused in their cephalic portion as 

 they are in adult Gyrinophilus, but remain separate throughout 

 their extent, as in developmental stages of the latter. A single 

 median dorsal fold, partially dividing the dorsal expansion, recalls 

 the similar slender fold ahead of and continuous with the fused 

 portion of the elevation in Gyrinophilus. 



The oviducts have large lumina and folded walls, as is to be 

 expected from the relatively large size of the ova in this form. 

 The bladder opens into the cloaca on its ventral side, somewhat 

 cephalic to the level of the oviducts. There is no dorsal diver- 



1 I am indebted to Dr. R. R. Humphrey for the material used in this study. 

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